Anyone elses partner like this since you've become pregnant?

Me and my man used to make love near enough everyday. Trying new things and positions all the time.

But since we've found out that we're having a baby hes been off sex completely. We hardly ever have it and when we do he finishes within minutes sometimes seconds.

He says he doesn't want to hurt the baby or my belly but I've told him 100 times that he wont hurt them. But he doesn't seem to believe me. Just makes me feel like his just using our sex to dump his load instead of wanting to make love to me. Plus we never do anything together anymore :(

What should I do?